Mass flow controller



FIG. 1 is a front perspective view of the mass flow controller of the present invention;

FIG. 2 is a front elevation view (the rear elevation is symmetrical);

FIG. 3 is a side elevation view (the opposite side elevation is symmetrical);

FIG. 4 is a top plan view; and,

FIG. 5 is a bottom plan view. 

The ornamental design for a mass flow controller, as shown and described. 